Device and method for less invasive surgical stabilization of pelvic fractures

ABSTRACT

Disclosed are an apparatus and its associated method for minimally invasive stabilization of anterior pelvic fractures. The pelvic stabilization system consisting of two rod shaped implants that may be surgically inserted subcutaneously or along the bone surface of each hemipelvis and a means of both linking the individual rods as well as rigidly securing the construct to the pelvis.

CROSS REFERENCE TO PREVIOUSLY FILED PROVISIONAL PATENTS

Continuation of previously submitted Provisional Application No.60/856,610 filed Nov. 6, 2006 is claimed with this application.

CROSS REFERENCE TO RELATED APPLICATIONS

U.S. Patent Documents 4,292,964 October, 1981 Ulrich 4,361,144 November,1982 Slätis et al. 4,454,876 June, 1984 Mears 5,108,397 April, 1992White 5,350,378 September, 1994 Cole et al. 6,162,222 December, 2000Poka et al. 6,340,362 January, 2002 Pierer et al. 6,440,131 August, 2002Haidukewych

STATEMENT OF FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

The disclosed invention was not funded through federal sources in anymanner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an implantable plate and/or rod system and itsassociated hardware used for the operation of implantation that isutilized to stabilize pelvic fractures.

2. Description of the Prior Art

Devices used to treat fracture of the pelvis currently fall under twogeneral classifications; internal fixation and external fixation.Internal fixation is typically utilized when the patient exhibitsunstable posterior pelvic fractures. See, for example, U.S. Pat. Nos.4,454,876; 5,108,397; 6,340,362 and 6,440,131. This type of fracturetends to be more complex with it involving multiple bony structures.Internal fixation addresses these clinical issues through open reductionand correction of misaligned bone segments that are subsequentlystabilized with a wide variety of plate and screw methods.

Anterior pelvic fractures or hemodynamically unstable patients arecandidates for external fixation. See, for example, U.S. Pat. Nos.4,292,964; 4,361,144; 5,350,378 and 6,162,222. External fixationconsists of stabilizing the pelvic ring with a rigid framework residingoutside the patient's body that is connected to the patient's pelvis viamultiple pins that penetrate through the patient's soft and hardtissues. Several frame types are currently utilized. Two of the morewidely deployed devices for external pelvic stabilization are theHoffmann 2 Inverted “A” Frame and the Ganz Pelvic C Clamp.

The application of external reduction and fixation for pelvic fracturesis advantageous compared to internal reduction and fixation due to itsspeed of deployment and lower level of technical training required forutilization. The primary disadvantages of external fixation of pelvicfractures include high risk of pin tract infections, general patientdiscomfort with external frame, physically blocks subsequent surgery onthe abdomen and difficult to fit obese patients. The disclosed systemmaintains many of the advantages of external fixation while eliminatingthe previously associated disadvantages.

It is the goal of the disclosed invention to provide a surgical hardwaresystem that will allow for submuscular or supramuscular/subcutaneousinternal fixation of anterior pelvic instability through a minimallyinvasive surgical approach.

BRIEF SUMMARY OF THE INVENTION

It is herein disclosed a method for stabilization of anterior pelvicfractures consisting of an orthopedic hardware system that may bepositioned between the skin and the muscle of the patient's lower torsoor alternatively along the pelvic bone surface and a series ofattachment devices that rigidly fix said hardware system to the bonystructures of the patient's pelvis.

In its preferred embodiment, the hardware system consists of twoelongated members that when joined together form a framework thatencompasses the anterior elements of the pelvis.

The design and curvature of the two elongated members is such so as tofacilitate their insertion and advancement between the skin and themuscle of the patient's lower torso or along the bony surface of thepelvis. The elongated members may also contain contours so as to ensureclearance of critical anatomical features located within the inguinalcanal such as the femoral nerve, artery and vein. The location ofelongated member's insertion is either over each of the patient'santerior inferior iliac spine prominences or iliac crest. The surgeonthen slides the elongated member around the anterior portion of thepelvis. The depth of the elongated member during advancement issubcutaneous and supramuscular or submuscular. Elongated memberadvancement is complete when the distal end of the device is positionedabove the patient's pubis. Elongated members are inserted from bothright and left sides. The elongated members may be in the general shapeof rods or plates. In one embodiment, the right and left elongatedmembers are linked over the patient's pubis by way of interlocking endsand multiple screw or pin placement. An alternative embodiment links thetwo elongated members together at the pubis through application of aclamp device that accepts both device ends. Another alternativeembodiment links the elongated member ends via a progressiveinterlocking produced by spring-loaded tabs along the male componentengaging cut-out slots along the female component. A further embodimentlinks the two device halves through a cable driven screw advancement. Afinal embodiment links the two device halves through attachment of acable linking the two medial ends of the anchored plates and externaltensioning of the cable. Device stabilization to the pelvis is obtainedthrough insertion of multiple screws or pins through the lateral deviceends and into the bone of the anterior inferior iliac spine or iliaccrest. Additional fixation of the device to the pelvis may be obtainedthrough insertion of multiple screws or pins through the plateconnecting means and into the underlying bone of the pubis region.Manipulation of the pelvic halves to obtain fracture reduction and platejoining may be accomplished through external loading applied via Schanzpins placed in the lateral portion of each plate half.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1. Female Plate Component of the Less Invasive, Multi-Holed,Variable Positioned Locked Pelvic Stabilization System. Shown is adrawing of the female plate components of the Less Invasive PelvicStabilization System.

FIG. 2. Male Plate Component of the Less Invasive, Multi-Holed, VariablePositioned Locked Pelvic Stabilization System. Shown is a drawing of themale plate components of the Less Invasive Pelvic Stabilization System.

FIG. 3. Male and Female Component of the Less Invasive, Multi-Holed,Variable Positioned Locked Pelvic Stabilization System. Shown is adrawing of the male and female components of the Less Invasive PelvicStabilization System joined together in a configuration as would beutilized clinically.

FIG. 4. Close-up of the interlocking components of the Less Invasive,Multi-Holed, Variable Positioned Locked Pelvic Stabilization System.Shown is a drawing of the male and female plate components prior tojoining.

FIG. 5. Close-up of the interlocking components of the Less Invasive,Multi-Holed, Variable Positioned Locked Pelvic Stabilization System in afully interlocked configuration.

FIG. 6. Close-up of the interlocking components of the Less Invasive,Multi-Holed, Variable Positioned Locked Pelvic Stabilization System in aslightly less than fully interlocked configuration.

FIG. 7. Close-up of the interlocking components of the Less Invasive,Multi-Holed, Variable Positioned Locked Pelvic Stabilization System inan interlocked configuration that is one-half of fully interlocked.

FIG. 8. Close-up of the interlocking components of the Less Invasive,Multi-Holed, Variable Positioned Locked Pelvic Stabilization System in aminimally interlocked configuration.

FIG. 9. Shown is the female component of the Spring Ratcheting LessInvasive Pelvic Stabilization System.

FIG. 10. Shown is the male component of the Spring Ratcheting LessInvasive Pelvic Stabilization System.

FIG. 11. Shown is the release clamp used to disengage the male andfemale plate components of the Spring Ratcheting Less Invasive PelvicStabilization System.

FIG. 12. Shown is the Cable Driven Invasive Pelvic Stabilization System.

FIG. 13. Shown is the female component of the Thread and Screw DrivenLess Invasive Pelvic Stabilization system.

FIG. 14. Shown is the male component of the Thread and Screw Driven LessInvasive Pelvic Stabilization system.

FIG. 15. Shown is a clinically usable positioning of a Clamp AdjustedLess Invasive Pelvic Stabilization system on a human pelvis.

FIG. 16 a. Shown is a clinically usable positioning of a Clamp/PlateLess Invasive Pelvic Stabilization system on a human pelvis.

FIG. 16 b. Shown is an expanded view of the medial segment for analternative configuration of the Clamp/Plate Less Invasive PelvicStabilization system.

DETAILED DESCRIPTION OF THE INVENTION

Figure one illustrates the female plate components of the Less Invasive,Multi-Holed, Variable Positioned Locked Pelvic Stabilization System. Thedevice is a smoothly arcing, circular rod made from typical metallicmaterials common to orthopedic devices such as stainless steel andtitanium alloys. The medial end of the device expands (103) to a radiusgreater than that of the remaining rod section to allow interconnectionwith the male component of the plate system. At the medial end of thefemale plate, a circular opening (101) leading to a hollow section withthe rod allows the male plate to interconnect with the female plate.Multiple screw holes run through the hollow, interlocking region of thefemale plate (102). The screw holes (102) may be of a standardconfiguration, a locking configuration or a variable angled, lockingconfiguration. The overall length of the rod will be variable so as tobetter match the anatomical dimensions of a given patient (104). Thedistal end of the rod has multiple screw holes to allow for mechanicalconnection to the bony structures of the pelvic rim. Multiple screwholes are positioned at the distal rod end (105) that may be of astandard configuration, a locking configuration or a variable angled,locking configuration. A circular recess (106) is positioned at thedistal rod end to allow for engagement of a Schanz pin connector forapplication of mechanical leverage during manipulation of the pelvicfracture.

Figure two illustrates the male plate components of the Less Invasive,Multi-Holed, Variable Positioned Locked Pelvic Stabilization System. Themedial end of the rod contains multiple holes (201) to allow screws topass through the rod thus anchoring it to the female plate and to theunderlying bony structures. As with the female rod, the rod length isvariable to match a wide range of patient sizes (202). Identical to thefemale rod, screw holes (203) and Schanz pin connectors (204) arelocated at the distal rod end.

Figure three illustrates the fully joined positions of the male andfemale rods. When the two components are linked they form a stable archthat spans the ventral aspect of the patient's pelvis. Linkage of thisstable construct to the fractured pelvis controls both halves of thepelvis and therefore stabilizes the fracture.

Figure four illustrates a close-up view of the medial ends of both thefemale (401) and male (402) rod components as they would approach eachother prior to interlocking. Both the male and female rods have a seriesof matching screw holes along their distal end. (403 and 404)

Figure five illustrates an expanded view of the female (501) and male(502) rod components fully interlocked. Two bone screws (503) are showntraveling through aligned screw holes in both the male and female rodcomponents. The bone screws path through the linked hardware and intothe underlying pelvic bone.

Figure six illustrates an expanded view of the female (601) and (602)male rod components slightly retracted from a fully interlockedposition. Bone screws (603) are inserted through the pair ofinterconnected rods in the same positions as the fully interconnectedrod configuration. Alternative screw positions are available aswarranted by the position of dense bone for reception of the protrudingbone screw.

Figure seven illustrates an expanded view of the female (701) and male(702) rod components in a position that is approximately one-halfinterlocked. Two full length screws (703) are utilized to attach thepelvic LISS hardware to the underlying pelvic bone while a thirdnon-penetrating, inter-rod screw (704) is placed centrally to aid in themechanical interlocking of the male and female rods.

Figure eight illustrates an expanded view of the female (801) and male(802) rod components in a configuration of minimal interlocking. Thefemale and male rod components are mechanically joined via two bonescrews (803) and one inter-rod screw (804).

Figure nine illustrates the female component of the Spring RatchetingLess Invasive Pelvic Stabilization System. Unique features of the femalecomponent of the Spring Ratcheting Less Invasive Pelvic StabilizationSystem include a series of slots through the sidewall of the rod thatare positioned at the male entry end of the component (901). Thefunction of these slots (901) is to allow mechanical retention of tabbedleaf springs embedded along the received male component. Also present atthe receiving end of the rod are two dorsal and pectoral flanges (902)containing locking screw holes (903). Locking screws are insertedthrough these holes to help mechanically secure the pelvic LISS to thepatient's pubis symphysis bone. As with the alternative embodiments ofthe pelvic LISS, the distal, non-receiving end of the female componentconsists of multiple locking screw holes (904) and a Schanz pinengagement port (905).

Figure ten illustrates the male component of the Spring Ratcheting LessInvasive Pelvic Stabilization System. Unique features of the malecomponent of the Spring Ratcheting Less Invasive Pelvic StabilizationSystem include a series of tabbed leaf springs (1001) embedded along thesurface of the lateral portion of the component. Upon insertion into thefemale component, the tabbed leaf springs are compressed. With furtherinsertion, the tabbed leaf springs engage with the slots along thefemale component. Successive insertion is possible to facilitate furtherfracture reduction while disengagement will be mechanically impeded dueto the interlocking of the leaf spring/slot combination. As with thealternative embodiments of the pelvic LISS, the distal end of the malecomponent consists of multiple locking screw holes (1004) and a Schanzpin engagement port (1005).

Figure eleven illustrates the novel tools for disengaging the male andfemale components of the Ratcheting Less Invasive Pelvic StabilizationSystem. Disengagement would be clinically needed during hardware removalafter bone healing has generated sufficient mechanical stability. Thecustom clamp device (1101) would be surgically inserted to encase themedial/linked ends of the male and female plates. The insets providedalong the clamp surface (1102) are designed to be of a depth sufficientto release the springs of the male plate from the slots of the femaleplate. Once the springs are freed, the male and female plates are freeto disengage and for hardware removal to proceed.

Figure twelve illustrates the Cable Driven Less Invasive PelvicStabilization System. The Pelvic Cable LISS could be utilized clinicallyas follows.

-   -   1. LISS plates are inserted subcutaneous or submuscular. Plates        are anchored via screws at the iliac crest and also possibly at        the pubis synthesis. One of the two plates (1201) has a hollow        tunnel with a cable running along its length. The cable has an        attachment feature at its end (1202) to securely capture the end        of the opposing plate (1203). The attachment feature may be a        locking feature such as coarse threading or a rotational        interlock.    -   2. Once plates are secured to each hemi-pelvis in proper        anatomic relation, the surgeon manipulates the cable from the        end of one plate and secures it to the end of the other plate        (1204). Standard surgical instruments would be used to        facilitate this maneuver.    -   3. Once the plates are linked through the cable, the cable is        tensioned at its exit point at the lateral plate end (1205).    -   4. The force provided by the cable tension should close any        misalignment between the pelvic halves (1206).    -   5. Once the fractured pelvis is brought back into anatomic        alignment, plates can be linked or additional screws placed.        Whether the tensioned cable is removed once the anatomy is        believed stable or the cable is left inside the construct under        some degree of tension is optional.

Figure Thirteen illustrates the female component of the Thread and ScrewDriven Pelvic LISS. The female rod component exhibits locking screwholes (1301) as well as Shanz pins connectors (1302) along its proximalend. The medial end of the female rod component exhibits a threadedinner surface (1303) for joining with the screw component of the maledevice and lateral flanges (1304) with a series of locking screw holes(1305).

Figure Fourteen illustrates the male component of the Thread and ScrewDriven Pelvic LISS. The male rod component contains a flexible cable(1401) that runs along the interior length of the rod. The medial end ofthe cable is attached to a rotating screw (1402) that is size and shapematched to engage with the female threaded medial portion (1303) of theassociated female rod component. The proximal end of the cable (1403) isfitted with a mechanical means for coupling with an external, rotatingdrive mechanism such as threading or a mechanical interlockingconfiguration. The proximal end of the male rod may be capped with athreaded end cap (1404) to limit access to bodily fluids once properclinical fixation is obtained. Proximal attachment of the device to thepatient's pelvic bone may be accomplished via insertion of bone screwthrough locking screw holes (1405) positioned along a lateral flange.Interoperative torque may be applied to the construct as an aid inobtaining proper alignment through a Shanz pin port (1406) locatedtoward the proximal end of the male rod component.

Figure Fifteen illustrates a Clamp Adjusted Pelvic Stabilization Systemas it would be positioned on the pelvis. On both the right and leftsides of the pelvis, rods arc around the pelvis from the iliac crest tothe pubis synthesis (1501). Proximal rod ends are secured to the pelvicbone via bone screws inserted through multiple, threaded screw holes(1502). Medial rod ends are secured to the pelvic bone and to each othervia a rod capturing clamp (1503) and screw fixed brackets (1504).

Figure Sixteen (a) illustrates a Clamp/Plate Pelvic Stabilization Systemas it could be positioned on the pelvis. On both the right and leftsides of the pelvis, rods arc around the pelvis from the iliac crest tothe pubis synthesis (1601). Proximal rod ends are secured to the pelvicbone via bone screws inserted through multiple, threaded screw holes(1602). Across the pubis synthesis, a rigid baseplate (1603) ispositioned and secured through placement of multiple bone screws (1604).Dual channels along the outer surface of the plate accept the medialends of the right and left rods. A clamping plate (1605) compresses therods into the baseplate via insertion of multiple locking screws (1606).

Figure Sixteen (b) illustrates an expanded view of the medial segment ofan alternative format for the Clamp/Plate Pelvic Stabilization System. Aplate (1607) is surgically positioned over the pelvic pubis and rigidlyanchored through insertion of multiple locking bone screws (1604). Themedial ends of the right and left hemipelvic rods (1601) are rigidlybound together via compressive forces applied through placement of acapping plate (1608) and insertion and tightening of screws (1609) thattravel through the capping plate and engage with threaded screw holeswithin the larger plate (1607) positioned beneath.

1. A device for orthopedic stabilization of fractures of the humanpelvis, wherein the associated hardware may be surgically positionedeither beneath the patient's skin and above that patient's muscle oragainst the surface of the patient's bone, comprising: a. two rod shapedimplants of length and curvature to span from the iliac crest of thehuman pelvis to the pubis synthesis of the human pelvis, one rodencompassing the right hemipelvis and the other rod encompassing theleft hemipelvis; b. a series of threaded holes penetrating through theproximal region of said rods, with correspondingly sized bone screws,that in combination, create a means of rigidly attaching the proximalportion of said rods to the underlying iliac crest bone; c. a mechanicallinkage to rigidly connect the medial extent of the left and right rods;d. a series of threaded holes penetrating through the medial region ofthe device with associated sized bone screws, that in combination,create a means of rigidly attaching the medial portion of said device tothe underlying pubis bone.
 2. The pelvic fracture stabilization deviceaccording to claim 1, wherein, said mechanical linkage connecting leftand right rods consists of mating male and female medial rod ends withmutual screw holes bisecting both male and female medial rod ends so asto produce a series of possible rod-to-rod mating positions, whereinperpendicularly inserted bone screws may simultaneously bisect male andfemale rods to subsequently engage in the pelvic bone of the pubissynthesis region.
 3. The pelvic fracture stabilization device accordingto claim 1, wherein, said mechanical linkage connecting left and rightrods consists of mating male and female medial rod ends withsequentially positioned, spring loaded members located along the outersurface of the male rod end and correspondingly spaced indentationslocated along the inner surface of the female rod end, of the same sizeand shape as the spring loaded members, so as to securely lock the maleand female rod ends together as they are progressively engaged.
 4. Thepelvic fracture stabilization device according to claim 1, wherein, saidmechanical linkage connecting left and right rods consists of a flexiblecable that when adequately tensioned may pull the two rod componentstogether and subsequently securely join their male and female medial rodends through the process of 1) through placement of bone screws throughthe rods and into the underlying pelvic bone, rigidly secure one rodcomponent to each hemipelvis, 2) allowing that one of the secured rodcomponents contains a flexible cable within its length, that exits fromits distal extent, surgically progress said cable from its startingposition at the end of one rod, across the gap between the two rods, andmechanically secure said cable to the medial end of the second rod, 3)increasingly tension the joining cable through uptake of the cableoutside of the patient's body, 4) as cable tension increases both rodends, and the associated hemipelvis, will be drawn together, 5) male andfemale rod ends mate and securing bone screws are inserted throughinterposed screw holes into underlying pelvic bone.
 5. The pelvicfracture stabilization device according to claim 1, wherein, saidmechanical linkage connecting left and right rods consists of matingmale and female medial rod ends via engagement of a threaded femalemedial rod segment with a cable driven, rotating screw segment locatedat the medial extreme of the male rod component, whereby the two rodsmay be progressively engaged through the rotation of a cable thattravels within the hollow interior of the male rod component, secured atone end to the rotating male screw segment and at the other end to anexternal rotary drive mechanism.
 6. The pelvic fracture stabilizationdevice according to claim 1, wherein, said mechanical linkage connectingleft and right rods consists of a rigid plate surgically positionedbetween the medial rod ends and the pelvic bone, wherein the plate maybe secured to the underlying pelvic bone via bone screw placement andthe right and left rod components may be secured to the plate via atraditional mechanical clamping mechanism.
 7. The pelvic fracturestabilization device according to claim 1, wherein, said mechanicallinkage connecting left and right rods consists of a screw-driven,clamping device that simultaneously holds rigid left and right rods atthe medial position of their overlapping, while rigid fixation of therods to the underlying pelvic bone is accomplished via individual rightand left clamps and screws that confine the said rods and rigidly holdthem to the underlying pelvic bone via bone screw placement.